// let obj = {
//     f: function () {
//         console.log(this);
//     }
// }

// obj.f();

// person 类
function Person(age) {
    this.age = age;
    this.setAge = function () {
        this.age++;
    }
}

function f() {
    console.log(this);
}

let person = new Person(10);
let person1 = new Person(20);

console.log(person.age);
console.log(person1.age);

person.setAge();

console.log(person.age);

f()